2 Federal rulings and regulations. In determining whether “taxable income,” “net

operating loss deduction” or any other deductions are computed for federal tax purposes under, or have the same meaning as provided by, the Internal Revenue Code, the department will use applicable rulings and regulations that have been duly promulgated by the commissioner of internal revenue, unless the director has created rules and regulations or has exercised discretionary powers as prescribed by statute which calls for an alternative method for determining “taxable income,” “net operating loss deduction” or any other deduction, or unless the department finds that an applicable internal revenue ruling or regulation is unauthorized according to the Iowa Code. This rule is intended to implement Iowa Code sections 422.7 and 422.9. [Editorial change: IAC Supplement 11/2/22]